To throw = echar, arrojar, tirar, lanzar. Puedes intercambiar los cuatro verbos en tus frases y no cambiará el significado de las mismas.

"lanzar" is used when you throw something and whose trajectory has a movement from right to left or vice versa like "lanzar un balón" "Tiro" is used in two diffetent meanigs, the first one when you drop something whose trayectory is modified by gravity I mean when something falls. like tira (it has another meaning too) eso!!! and the second one is used when you want to "lanzar" something but with a specific purpose or goal in a sport. like: El jugador tiro desde medio campo or el basquetbolista tiro una canasta de tres puntos" "Echar" is used when you get something into I mean when you put something within a space like a box, like "echa la basura en el bote or echalo a la basura or echalo en la caja", I can explain you better if we make touch as friends in italki or skype or messenger. Goog luck my friend.